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Ajutati-ma cu suma lui Gauss: 1+2+3........+99+100=; 1+2+3+..........+88+99=; 1+2+3+.........+99=.

Răspuns :

aplici de fiecare data aceeasi formula 

1+2+3+...+n=n(n+1)/2

Adica'1+2+3+...+99+100 = 100*101/2 = 50*101
1+2+3+...+88 = 88*89/2 = 44*89+99
1+2+3+...+99 = 99*100/2 = 99*50
1+2+3........+99+100=5 050
=100x(1+100):2=
=50x101=
=5050

1+2+3+..........+99=4950
=99x(1+99):2=
=99x100:2=
=99x50=
=4950